Inner circular seam automatic welding equipment and inner circular seam automatic welding method for large-diameter steel pipe

Abstract

The invention discloses automatic welding equipment for an inner circular seam of a large-diameter steel pipe and an automatic welding method for the inner circular seam. The automatic welding equipment comprises an equipment main machine, a welding working device and a connecting device, and a walking mechanism is arranged on the equipment main machine and / or the welding working device; the connecting device comprises a first connecting plate connected with the equipment main machine, a second connecting plate connected with the welding working device and a deviation mechanism used for connecting the first connecting plate and the second connecting plate and enabling the second connecting plate to deviate relative to the radial plane of the steel pipe, and a first positioning mechanism is arranged on the equipment main machine. A second positioning mechanism is arranged on the welding working device; the deviation function of the connecting mechanism can achieve vibration reduction, the situation that the work and operation of a welding working device are affected by vibration of an equipment host is avoided, and therefore the welding quality is guaranteed, and walking and positioning are suitable for the conditions that the axes of two steel pipes are not coincident, and the straightness and roundness of the steel pipes do not reach the standard. Therefore, the automatic welding equipment for the inner circular seam of the large-diameter steel pipe can still complete automatic welding.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline welding, and in particular, to an automatic inner annular seam welding device for large diameter steel pipes. In addition, the present invention also relates to an automatic inner annular seam welding method for large diameter steel pipes comprising using the automatic inner annular seam welding device for large diameter steel pipes. Background Art

[0002] In the on-site manufacturing and installation of water conservancy and hydropower steel pipes, the steel pipes are usually welded into sections within 6 meters. The steel pipes are transported to the installation site by special car trailers or rail trolleys, and then assembled and welded. The on-site welding quality requirements are high, the workload is large, and the welding process is difficult. At present, the welding of steel pipe assembly welds is mainly done manually, which has the problems of high labor intensity, unstable operation quality, and low efficiency. Traditional manual welding can no longer meet the needs of on-site construction.

[0003] In order to improve welding efficiency, automatic welding devices for inner circumferential seams of steel pipes have emerged. Since the assembly of steel pipes relies on rail trolleys, it is difficult to adjust the angle, roundness, assembly spacing and the coincidence of the axes of the two sections of steel pipes during the assembly process. There will be problems such as the axes of the steel pipes not coinciding with each other and the roundness of the steel pipes not meeting the requirements.

[0004] For example, Chinese patent CN216730166 U discloses an automatic welding device for steel pipes in tunnels. By setting a circular ring-shaped sliding component, the welding gun can move circumferentially with the inner wall of the large steel pipe in the tunnel, thereby automatically welding the circular end face of the steel pipe. On the one hand, as the construction progresses, the welding work station will constantly change, and the automatic welding device cannot move autonomously, which is very inconvenient to construct in the steel pipe, which will reduce the efficiency of the overall welding construction; on the other hand, because the slide rail can be attached to the inner wall of the steel pipe in the tunnel through the positioning module, when the roundness of the steel pipe cannot meet the requirements, the circular track is difficult to lay, which will lead to the situation that welding cannot be effectively implemented.

[0005] Another example is a steel pipe welding trolley disclosed in Chinese patent CN201685037 U, which drives the steel pipe to rotate through a reducer, and performs circumferential welding through a welding operation frame on a crossbeam, thereby realizing on-site installation and manufacturing of long and large steel pipes or multiple steel pipe connections. Since the reducer, welding operation frame and electromechanical control system are installed on the crossbeam, the vibration of the reducer during rotation will affect the normal welding work of the welding mechanism, resulting in poor welding quality. Summary of the invention

[0006] The present invention provides an automatic welding device and method for the inner annular seam of a large-diameter steel pipe, so as to solve the technical problems that the automatic welding equipment in the prior art is inconvenient to construct inside the steel pipe, is difficult to use when the axes between the steel pipes do not coincide, the roundness of the steel pipe exceeds the standard, and the welding quality is poor.

[0007] According to one aspect of the present invention, there is provided an automatic welding device for the inner annular seam of a large diameter steel pipe, comprising an equipment main unit for providing power, a welding working device and a connecting device for welding the inner annular seam, the equipment main unit and / or the welding working device being provided with a walking mechanism, the connecting device comprising a first connecting plate connected to the equipment main unit, a second connecting plate connected to the welding working device, and an offset mechanism for connecting the first connecting plate and the second connecting plate and allowing the second connecting plate to be offset relative to the radial plane of the steel pipe, the equipment main unit being provided with a first positioning mechanism for fixing the position of the equipment main unit along the axial direction of the steel pipe, and the welding working device being provided with a second positioning mechanism for keeping the welding working device coaxial with the steel pipe.

[0008] Furthermore, the offset mechanism includes a first sleeve arranged on the first connecting plate, a second sleeve arranged on the second connecting plate, a sliding rod slidably connected to the first sleeve and the second sleeve, and a buffer member sleeved on the sliding rod, and limit blocks are respectively arranged at both ends of the sliding rod to prevent the sliding rod from slipping, and the inner diameters of the first sleeve and the second sleeve are larger than the outer diameter of the sliding rod to form an offset gap.

[0009] Furthermore, the walking mechanism includes a driving wheel arranged on the equipment main body, a telescopic wheel group arranged on the equipment main body and retractable in the horizontal direction, a first guide wheel group arranged on the equipment main body, a second guide wheel group arranged on the welding work device, and a lifting mechanism for driving the telescopic wheel group to move in the vertical direction.

[0010] Furthermore, the first guide wheel group and the second guide wheel group are both distributed in a figure eight shape.

[0011] Furthermore, the first positioning mechanism includes a side main support mechanism arranged on the main body of the equipment and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe, and a side auxiliary support mechanism arranged on the main body of the equipment and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe. The side main support mechanism includes a first supporting cylinder that can be extended and retracted in the horizontal direction and an arc-shaped support block arranged on the free end of the first supporting cylinder and adapted to the inner wall of the steel pipe. The side auxiliary support mechanism has the same structure as the side main support mechanism.

[0012] Furthermore, the side main support mechanism is arranged on one end of the device main body away from the telescopic wheel group, and the side auxiliary support mechanism is arranged on one end of the device main body close to the telescopic wheel group, and the support area of ​​the arc-shaped support block on the side main support mechanism is larger than the support area of ​​the arc-shaped support block on the side auxiliary support mechanism.

[0013] Furthermore, the second positioning mechanism includes an annular positioning frame arranged on the welding work device, second supporting cylinders evenly arranged along the circumference of the annular positioning frame, a balancing frame arranged on the free end of the second supporting cylinder, a ball arranged on the balancing frame, and a pressure sensor for monitoring the oil pressure of the second supporting cylinder. The free end of the second supporting cylinder is connected to the balancing frame through a universal joint, and the second supporting cylinder and the pressure sensor are arranged in a one-to-one correspondence.

[0014] Furthermore, the welding working device includes a track mechanism, a welding mechanical arm, a connecting sleeve and a welding wire feeding mechanism, the track mechanism includes a circular track arranged on the connecting sleeve 23, a driving rack arranged on the circular track, and a mobile trolley arranged on the driving rack, the welding mechanical arm includes a mechanical arm arranged on the mobile trolley, a welding gun and a visual system arranged on the mechanical arm, the welding wire feeding mechanism includes a side connection frame connected to the connecting device, the side connection frame is provided with the wire feeder, the wire reel and the gun cleaner, one end of the connecting sleeve is connected to the side connection frame, and the other end is connected to the annular positioning frame.

[0015] Furthermore, the equipment host includes a host body, on which a power supply, an electric control box, a pump station and a mounting plate for connecting the connecting device are arranged.

[0016] According to another aspect of the present invention, there is also provided a method for automatic welding of inner annular seams of large diameter steel pipes, using the above-mentioned automatic welding equipment for inner annular seams of large diameter steel pipes, which comprises the following steps:

[0017] S1. Adjust the installation position of the connecting device and the side frame and the extension length of the second positioning mechanism according to the diameter of the steel pipe to be welded, and adjust the lifting mechanism so that the horizontal extension direction of the telescopic wheel group coincides with the horizontal radial direction of the steel pipe to be welded;

[0018] S2, retract the first supporting cylinder, retract the telescopic wheel group and the second supporting cylinder, hoist the inner annular seam automatic welding equipment of the large diameter steel pipe into the assembled steel pipe to be welded,

[0019] S3, extend the telescopic wheel group so that the telescopic wheel group is rollingly connected with the inner wall of the steel pipe to be welded, extend the second supporting oil cylinder so that the ball of the balance frame on the bottom end of the annular positioning frame is rollingly connected with the inner wall of the steel pipe to be welded, start the walking mechanism to drive the automatic welding equipment for the inner annular seam of the large-diameter steel pipe to move to the working place, and ensure that the distance between the welding robot arm and the weld is within the preset range;

[0020] S4, extending the first supporting oil cylinder so that the arc-shaped supporting block of the side main supporting mechanism and the arc-shaped supporting block of the side auxiliary supporting mechanism abut against the inner wall of the steel pipe to be welded, and adjusting and fixing the relative position of the main machine of the equipment and the steel pipe to be welded;

[0021] S5, extending the second supporting oil cylinder so that the balls on all the balancing frames abut against the inner wall of the steel pipe to be welded, thereby positioning the relative position of the welding working device and the steel pipe to be welded;

[0022] S6. Start the visual system to check the positioning of the track mechanism, welding robot arm, and the equipment status of the wire feeder, robot arm, and welding gun.

[0023] S7. Carry out preparatory work before welding, grind and preheat the annular seam;

[0024] S8, Circumferential seam automated welding and root cleaning;

[0025] S9, weld post-processing, completing the welding of a circumferential seam;

[0026] S10, retract the second supporting oil cylinder, keep the ball of the balance frame on the bottom end of the annular positioning frame rollingly connected with the inner wall of the steel pipe to be welded, retract the first supporting oil cylinder, so that the arc support block of the side main supporting mechanism and the arc support block of the side auxiliary supporting mechanism are out of contact with the inner wall of the steel pipe to be welded;

[0027] S11. Repeat steps S3 to S10 to weld the next annular seam.

[0028] The present invention has the following beneficial effects:

[0029] The automatic welding equipment for inner annular seams of large-diameter steel pipes of the present invention drives the entire equipment forward or backward in the steel pipe through a walking mechanism, so as to facilitate adjustment of the relative position between the equipment and the annular weld of the steel pipe; when the equipment moves to the working point, the relative position of the main machine of the equipment and the steel pipe is positioned by the first positioning mechanism, and the relative position of the welding working device and the steel pipe is positioned by the second positioning mechanism. Since the second connecting plate of the connecting mechanism can be offset relative to the radial plane of the steel pipe, on the one hand, the positioning of the welding working device can be effectively adjusted and is not affected by the positioning of the main machine of the equipment, and can prevent the welding working device and the standby main machine from being positioned non-concentrically and causing torsional damage to the connecting mechanism. On the other hand, vibration reduction can be achieved through the connecting mechanism to avoid the vibration of the main machine of the equipment from affecting the work and operation of the welding working device, thereby ensuring the welding quality. In addition, the offset function of the connecting mechanism can adapt to walking and positioning when the axes of the two sections of steel pipes do not overlap, the straightness of the steel pipes exceeds the standard, and the roundness does not meet the standard, so that the automatic welding equipment for inner annular seams of large-diameter steel pipes can still complete automatic welding; it is suitable for automatic welding of all-position welding of inner annular seams in the tunnel position of 2-3 meter diameter steel pipes.

[0030] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 It is a structural schematic diagram of an automatic welding device for inner annular seam of a large diameter steel pipe according to a preferred embodiment of the present invention;

[0033] Figure 2 It is a structural schematic diagram of another perspective of the automatic welding equipment for inner annular seam of large diameter steel pipe according to a preferred embodiment of the present invention;

[0034] Figure 3 It is a structural diagram of a device host of a preferred embodiment of the present invention;

[0035] Figure 4 is a structural schematic diagram of a first positioning mechanism in a preferred embodiment of the present invention;

[0036] Figure 5 It is a structural schematic diagram of a welding working device according to a preferred embodiment of the present invention;

[0037] Figure 6 is a structural schematic diagram of a welding robot arm according to a preferred embodiment of the present invention;

[0038] Figure 7It is a structural schematic diagram of a welding wire feeding mechanism according to a preferred embodiment of the present invention;

[0039] Figure 8 is a schematic structural diagram of a connecting device according to a preferred embodiment of the present invention;

[0040] Fig. 9 It is a structural schematic diagram of the walking mechanism of a preferred embodiment of the present invention;

[0041] Fig.10 It is a structural schematic diagram of the second positioning mechanism of the preferred embodiment of the present invention.

[0042] Legend:

[0043] 100, steel pipe; 1, equipment host; 11, host body; 12, power supply; 13, electric control box; 14, pump station; 15, installation plate; 16, maintenance door; 17, gas cylinder storage area; 18, mechanical arm control cabinet; 2, welding work device; 21, welding mechanical arm; 211, mechanical arm; 212, welding gun; 22, track mechanism; 221, circular track; 222, driving rack; 223, mobile trolley; 23, connecting sleeve; 24, welding wire feeding mechanism; 241, side frame; 242, wire feeder; 243, wire reel; 244, inspection port; 3, connecting device; 31, first Connecting plate; 32, second connecting plate; 33, offset mechanism; 331, first sleeve; 332, second sleeve; 333, slide bar; 334, buffer; 335, limit block; 4, walking mechanism; 41, driving wheel; 42, telescopic wheel group; 43, first guide wheel group; 44, second guide wheel group; 5, first positioning mechanism; 51, side main support mechanism; 52, side auxiliary support mechanism; 511, first support cylinder; 512, arc support block; 6, second positioning mechanism; 61, annular positioning frame; 62, second support cylinder; 63, balance frame; 64, ball; 65, universal joint. DETAILED DESCRIPTION

[0044] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0045] Please also read Figures 1 to 10The automatic inner annular seam welding equipment for large-diameter steel pipes of this embodiment includes an equipment main body 1 for providing power, a welding working device 2 for welding inner annular seams and a connecting device 3. A walking mechanism 4 is arranged on the equipment main body 1 and / or the welding working device 2. The connecting device 3 includes a first connecting plate 31 connected to the equipment main body 1, a second connecting plate 32 connected to the welding working device 2, and an offset mechanism 33 for connecting the first connecting plate 31 and the second connecting plate 32 and allowing the second connecting plate 32 to be offset relative to the radial plane of the steel pipe 100. A first positioning mechanism 5 for fixing the position of the equipment main body 1 along the axial direction of the steel pipe 100 is arranged on the equipment main body 1, and a second positioning mechanism 6 for keeping the welding working device 2 and the steel pipe 100 coaxial is arranged on the welding working device 2.

[0046] The automatic welding equipment for inner annular seams of large-diameter steel pipes of this embodiment drives the entire equipment forward or backward in the steel pipe 100 through the walking mechanism 4, so as to facilitate adjustment of the relative position between the equipment and the annular weld of the steel pipe; when the equipment moves to the working point, the relative position of the equipment main body 1 and the steel pipe 100 is positioned by the first positioning mechanism 5, and the relative position of the welding working device 2 and the steel pipe 100 is positioned by the second positioning mechanism 6. Since the second connecting plate 32 of the connecting mechanism 3 can be offset relative to the radial plane of the steel pipe 100, on the one hand, the positioning of the welding working device 2 can be effectively adjusted without being affected by the positioning of the equipment main body 1 On the one hand, it can prevent the torsional damage to the connecting mechanism 3 caused by the eccentric positioning of the welding working device 2 and the standby main machine 1. On the other hand, it can achieve vibration reduction through the connecting mechanism 3 to avoid the vibration of the equipment main machine 1 affecting the work and operation of the welding working device 2, thereby ensuring the welding quality. In addition, the offset function of the connecting mechanism 3 can adapt to walking and positioning when the axes of the two sections of steel pipes do not coincide, the straightness of the steel pipes exceeds the standard, and the roundness does not meet the standard, so that the automatic welding equipment for the inner ring seam of large-diameter steel pipes can still complete automatic welding; it is suitable for automatic welding of the inner ring seam of 2-3 meter diameter steel pipes in the tunnel position. Full-position welding.

[0047] Optionally, the offset mechanism 33 is a universal joint, which has a simple structure and low production cost.

[0048] like Figure 7 and Figure 8As shown, in this embodiment, the offset mechanism 33 includes a first sleeve 331 arranged on the first connecting plate 31, a second sleeve 332 arranged on the second connecting plate 32, a sliding rod 333 slidably connected to the first sleeve 331 and the second sleeve 332, and a buffer 334 sleeved on the sliding rod 333, and two ends of the sliding rod 333 are respectively provided with limit blocks 335 for preventing the sliding rod 333 from slipping off. The inner diameters of the first sleeve 331 and the second sleeve 332 are larger than the outer diameter of the sliding rod 333 to form an offset gap; the sliding rod 333 slides relative to the first sleeve 331 and the second sleeve 332 in the axial direction, and there is also an offset space in the radial direction. When the axis of the pipes do not coincide, and the straightness and roundness of the steel pipes do not meet the standards, when the first positioning mechanism 5 and the second positioning mechanism 6 are positioned respectively, the second connecting plate 32 and the offset mechanism 33 that enables the second connecting plate 32 to be offset relative to the radial plane of the steel pipe 100 are used to prevent torsional damage to the connecting mechanism 3 when the positioning is not concentric; when welding is completed, the first positioning mechanism 5 and the second positioning mechanism 6 cancel the positioning, and the buffer 334 can drive the second connecting plate 32 to reset; by selecting the size of the first sleeve 331, the second sleeve 332 and the sliding rod 333, the offset gap can be adjusted, thereby limiting the offset amount of the second connecting plate 32 and preventing the offset displacement from being too large. Optionally, the buffer 334 is a spring, an elastic bellows or a rubber sleeve. Optionally, multiple offset mechanisms 33 are evenly arranged in the circumferential direction.

[0049] like Figure 3 , Figure 4 and Figure 5 As shown, in this embodiment, the walking mechanism 4 includes a driving wheel 41 arranged on the equipment main body 1, a telescopic wheel group 42 arranged on the equipment main body 1 and capable of being telescopic in the horizontal direction, a first guide wheel group 43 arranged on the equipment main body 1, a second guide wheel group 44 arranged on the welding working device 2, and a lifting mechanism for driving the telescopic wheel group 42 to move in the vertical direction; the first guide wheel group 43 and the driving wheel 41 support the equipment main body 1, the first guide wheel group 43 supports the welding working device 2, and the entire equipment is driven by the driving wheel 41 to move on the steel pipe 10 0, so as to facilitate the movement of the working point and the adjustment of the relative position between the whole equipment and the steel pipe circumferential weld during welding; two telescopic wheel groups 42 are symmetrically arranged on both sides of the equipment main body 1, and each telescopic wheel group 42 includes two first rollers arranged up and down. When constructing steel pipes of different diameters, the telescopic wheel group 42 adjusts its height in the steel pipe 100 through the lifting mechanism to ensure that the two first rollers arranged up and down are symmetrical with respect to the horizontal radial direction of the steel pipe 100, thereby ensuring that the equipment can stably move in steel pipes 100 of different diameters.

[0050] like Figure 5 and Fig. 9As shown, in this embodiment, the first guide wheel group 43 and the second guide wheel group 44 are both distributed in an eight-shaped shape. The first guide wheel group 43 includes two second rollers, which are distributed in an eight-shaped shape and are symmetrically arranged in the vertical and diametrical directions relative to the steel pipe 100. The supporting force of the inner wall of the steel pipe 100 on the second rollers can be decomposed into vertical force components and horizontal force components, which can improve the stability of the equipment host 1. The second guide wheel group 44 has the same structure as the first guide wheel group 43, which can improve the stability of the welding work device 2, thereby ensuring the welding quality.

[0051] like Figure 3 and Figure 4 As shown, in this embodiment, the first positioning mechanism 5 includes a side main support mechanism 51 arranged on the equipment main body 1 and can be extended and retracted in the horizontal direction to abut the inner wall of the steel pipe 100, and a side auxiliary support mechanism 52 arranged on the equipment main body 1 and can be extended and retracted in the horizontal direction to abut the inner wall of the steel pipe 100. The side main support mechanism 51 includes a first supporting cylinder 511 that can be extended and retracted in the horizontal direction and an arc-shaped support block 512 arranged on the free end of the first supporting cylinder 511 and adapted to the inner wall of the steel pipe 100. The side auxiliary support mechanism 52 has the same structure as the side main support mechanism 51; the first supporting cylinders 511 of the side main support mechanism 51 and the side auxiliary support mechanism 52 are extended, so that the arc-shaped support block 512 abuts the inner wall of the steel pipe 100, which can ensure that the equipment main body 1 is stably and reliably fixed in the steel pipe 100 to be welded, avoiding affecting the working environment of the welding mechanism.

[0052] like Figure 3 and Figure 4 As shown, in this embodiment, the side main support mechanism 51 is arranged on the end of the equipment main body 1 away from the telescopic wheel group 42, and the side auxiliary support mechanism 52 is arranged on the end of the equipment main body 1 close to the telescopic wheel group 42. The support area of ​​the arc support block 512 on the side main support mechanism 51 is larger than the support area of ​​the arc support block 512 on the side auxiliary support mechanism 52; due to the supporting function of the telescopic wheel group 42, the side auxiliary support mechanism 52 can select a smaller arc support block 512, which can correspondingly reduce the parameters of the first supporting cylinder 511 of the side auxiliary support mechanism 52, thereby reducing the cost; and the horizontal component force provided by the first guide wheel group 43 on one side of the side main support mechanism 51 is relatively small, so a large cylinder is selected to provide a larger supporting force to ensure the stability of positioning, and the inner wall surface of the steel pipe 100 is coated. In order to prevent the arc support block 512 of the side main support mechanism 51 from damaging the coating, increasing the area of ​​the arc support block 512 can disperse the pressure, thereby protecting the coating on the inner wall surface of the steel pipe 100.

[0053] like Fig.10As shown, in this embodiment, the second positioning mechanism 6 includes an annular positioning frame 61 arranged on the welding work device 2, second supporting cylinders 62 uniformly arranged along the circumference of the annular positioning frame 61, a balancing frame 63 arranged on the free end of the second supporting cylinder 62, a ball 64 arranged on the balancing frame 63 and a pressure sensor for monitoring the oil pressure of the second supporting cylinder 62, the free end of the second supporting cylinder 62 is connected to the balancing frame 63 through a universal joint 65, and the second supporting cylinder 62 and the pressure sensor are arranged one by one; the plurality of second supporting cylinders 62 are synchronously telescopic, and the balancing frame 63 and the first The free ends of the two supporting cylinders 62 are connected by a universal joint 65, and the four balls 64 on the balance frame 63 are rollingly connected to the inner wall of the steel pipe 100. During positioning, each second supporting cylinder 62 automatically adjusts the supporting extension length by pressure sensing. The four balls 64 can share the pressure of the second supporting cylinder 62 to avoid damage to the coating on the inner wall of the steel pipe 100. The universal joint 65 can enable the balance frame 63 to be offset, thereby adapting to the working condition when the roundness of the steel pipe exceeds the standard to a certain extent. The positioning is reliable and ensures that the coaxiality of the track mechanism 22 of the welding work device 2 is closer to the steel pipe 100.

[0054] like Figure 5 , Figure 6 and Figure 7As shown, in this embodiment, the welding working device 2 includes a track mechanism 22, a welding mechanical arm 21, a connecting sleeve 23 and a welding wire feeding mechanism 24, the track mechanism 22 includes an annular track 221 arranged on the connecting sleeve 23, a driving rack 222 arranged on the annular track 221, and a mobile trolley 223 arranged on the driving rack 222, the welding mechanical arm 21 includes a mechanical arm 211 arranged on the mobile trolley 223, a welding gun 212 and a visual system arranged on the mechanical arm 211, the welding wire feeding mechanism 24 includes a side frame 241 connected to the connecting device 3, and a wire feeder 242, a welding wire reel 243 and a gun cleaner are arranged on the side frame 241, one end of the connecting sleeve 23 is connected to the side frame 241, and the other end is connected to the annular positioning frame 61; the side frame 241 and the connecting sleeve 23 The ring positioning frame 61 is coaxially connected, and the balance frame 63 on the ring positioning frame 61 can produce an offset, which is not affected by the roundness of the steel pipe 100, ensuring that the second positioning mechanism 6 accurately positions the welding working device 2, and the positioning is reliable and the coaxiality of the track mechanism 22 of the welding working device 2 and the steel pipe 100 is closer, thereby reducing the recognition distance deviation of the visual system, thereby ensuring the quality of automatic welding of the steel pipe annular seam. The mechanical arm 211 moves in a circle on the ring track 221 through the mobile trolley 223, and the welding efficiency distribution of each mechanical arm 211 can be adjusted at will, and the mechanical arm 211 will not be idle, and the welding efficiency is high; the wire feeder 242, the welding wire reel 243 and the gun cleaner are arranged at the welding working end of the side frame 241, which is convenient for the personnel at the working end to observe and replace consumables such as welding wire. Optionally, the mechanical arm 211 is a six-axis mechanical arm, which is flexible to operate and has a wide range of applications. Optionally, three mobile carriages 223 are arranged on the driving rack 222, and each mobile carriage 223 is respectively provided with a welding mechanical arm 21, which can perform segmented welding, layered welding or circular welding, and has a flexible working mode and a variety of adaptable methods. When welding circular welds, the workload can be effectively distributed, and the utilization rate and work efficiency of the welding work device 2 can be improved. Optionally, an inspection port 244 is provided on the side frame 241 for easy observation and maintenance by personnel.

[0055] like Figure 3 and Figure 4As shown, in this embodiment, the equipment host 1 includes a host body 11, on which a power supply 12, an electric control box 13, a pump station 14 and a mounting plate 15 for connecting the connecting device 3 are arranged; the host body 11 serves as a frame, the mounting plate 15 is connected to the first connecting plate 31, the power supply 12 provides power for the entire inner ring seam automatic welding equipment, the electric control box 13 is used for welding working device 2, walking mechanism 4, first positioning mechanism 5, second positioning mechanism 6 control and data processing, the electric control box 13 is arranged at the tail end of the host body 11 for centralized maintenance, and the pump station 14 provides pressure oil for the entire inner ring seam automatic welding equipment. Optionally, a maintenance door 16 is arranged on the host body 11 for maintenance personnel to overhaul. Optionally, a gas cylinder storage area 17 is arranged on the host body 11, and gas cylinders are placed in the gas cylinder storage area 17 to provide a high-pressure gas source for the entire inner ring seam automatic welding equipment. Optionally, a robot arm control cabinet 18 is arranged on the host body 11, and the control cabinet of the welding working device 2 is arranged separately inside the host body 11, which can simplify the circuit layout in the electric control box 13 and facilitate the separate maintenance and regulation of the control system of the welding robot arm 21. Optionally, an operation box and / or a remotely connected computer or electric control remote controller are arranged in the electric control box 13.

[0056] A method for automatically welding the inner annular seam of a large diameter steel pipe, using the above-mentioned automatic welding device for welding the inner annular seam of a large diameter steel pipe, comprises the following steps:

[0057] S1. According to the diameter of the steel pipe 100 to be welded, the installation positions of the connecting device 3 and the side frame 241 and the extension length of the second positioning mechanism 6 are adjusted so that the annular positioning frame 61 of the second positioning mechanism 6 is coaxial with the steel pipe 100 to be welded, and the lifting mechanism is adjusted so that the horizontal extension direction of the telescopic wheel group 42 coincides with the horizontal radial direction of the steel pipe 100 to be welded;

[0058] S2, retract the first supporting cylinder 511, retract the telescopic wheel group 42 and the second supporting cylinder 62, and hoist the inner annular seam automatic welding equipment of the large diameter steel pipe into the assembled steel pipe 100 to be welded.

[0059] S3, extend the telescopic wheel group 42 so that the telescopic wheel group 42 is rollingly connected with the inner wall of the steel pipe 100 to be welded, extend the second supporting oil cylinder 62 so that the ball 64 of the balance frame 63 on the bottom end of the annular positioning frame 61 is rollingly connected with the inner wall of the steel pipe 100 to be welded, start the walking mechanism 4 to drive the automatic welding equipment for the inner annular seam of the large-diameter steel pipe to move to the working place, and ensure that the distance between the welding robot arm 21 and the weld is within a preset range;

[0060] S4, extend the first supporting cylinder 511, so that the arc-shaped supporting block 512 of the side main supporting mechanism 51 and the arc-shaped supporting block 512 of the side auxiliary supporting mechanism 52 abut against the inner wall of the steel pipe 100 to be welded, and adjust and fix the relative position of the main machine 1 and the steel pipe 100 to be welded;

[0061] S5, extending the second supporting oil cylinder 62 so that the balls 64 on all the balancing frames 63 abut against the inner wall of the steel pipe 100 to be welded, thereby positioning the relative position of the welding working device 2 and the steel pipe 100 to be welded;

[0062] S6, start the visual system to check the positioning of the track mechanism 22, the welding robot arm 21 and the equipment status of the wire feeder 242, the robot arm 211 and the welding gun 212,

[0063] S7. Carry out preparatory work before welding, grind and preheat the annular seam;

[0064] S8, Circumferential seam automated welding and root cleaning;

[0065] S9, weld post-processing, completing the welding of a circumferential seam;

[0066] S10, retract the second supporting oil cylinder 62, keep the ball 64 of the balance frame 63 on the bottom end of the annular positioning frame 61 rollingly connected with the inner wall of the steel pipe 100 to be welded, retract the first supporting oil cylinder 511, so that the arc support block 512 of the side main supporting mechanism 51 and the arc support block 512 of the side auxiliary supporting mechanism 52 are out of contact with the inner wall of the steel pipe 100 to be welded;

[0067] S11. Repeat steps S4 to S10 to weld the next annular seam.

[0068] The present invention adopts a welding robot arm 21 to realize the automatic welding of the annular seam of the inner wall of the steel pipe. The welding robot arm 21 is a programming-free welding method. It adopts a visual system to accurately identify the geometric shape of the groove, the robot automatically lays out the position and posture planning, and independently realizes the robot swing welding and variable parameter process package, realizes the robot swing welding mode and path customization, and the welding process current voltage and other parameters adjustment, effectively solves the variable gap and thermal deformation compensation adaptive control, and finally realizes full-position full-automatic welding; the second positioning mechanism 6 installed in conjunction with the welding robot arm 21 is an annular positioning device, which can fix the welding work device 2 and position the axis line of the welding work device 2 near the axis line of the steel pipe, thereby reducing the recognition distance deviation of the visual system; the multiple second support cylinders 62 of the second positioning mechanism 6 are synchronously retractable, and each second support cylinder 62 relies on pressure sensing to automatically adjust the support extension length, and the positioning is reliable and ensures that the coaxiality of the welding mechanism and the steel pipe is closer; the walking mechanism 4 drives the whole The equipment can move freely in the steel pipe to realize the forward and backward functions, which is convenient for moving the working point and adjusting the relative position between the equipment and the steel pipe ring weld during welding; when constructing steel pipes of different diameters, the height of the telescopic wheel group 42 can be adjusted to ensure that the telescopic wheel group 42 can adapt to the stable movement within the diameters of different steel pipes; the first positioning mechanism 5 can ensure that when the welding working device 2 is working, the main body 1 of the equipment is stably and reliably fixed in the steel pipe to be welded, without affecting the working environment of the welding mechanism; since the main body 1 of the equipment and the welding working device 2 respectively have their own positioning mechanisms, the connecting mechanism 3 adopts a flexible connection method to connect the main body 1 of the equipment and the welding working device 2, which can ensure that the relative position of the first connecting plate 31 and the second connecting plate 32 is adjustable and does not separate from each other, and prevents torsional damage to the connecting mechanism 3 when the positioning is not concentric; the installation position of the side frame 241 and the second connecting plate can be adjusted, thereby adjusting the relative position of the welding working device 2 and the main body 1 of the equipment to adapt to different steel pipe diameters.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automatic welding device for inner annular seams of large diameter steel pipes, characterized in that: The invention comprises a main device (1) for providing power, a welding working device (2) for welding inner annular seams, and a connecting device (3); the main device (1) and / or the welding working device (2) are provided with a walking mechanism (4); the connecting device (3) comprises a first connecting plate (31) connected to the main device (1), a second connecting plate (32) connected to the welding working device (2), and an offset mechanism (33) for connecting the first connecting plate (31) and the second connecting plate (32) so that the second connecting plate (32) can be offset relative to the radial plane of a steel pipe; the main device (1) is provided with a first positioning mechanism (5) for fixing the position of the main device (1) along the axial direction of the steel pipe; and the welding working device (2) is provided with a second positioning mechanism (6) for keeping the welding working device (2) and the steel pipe coaxial.

2. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 1 is characterized in that: The offset mechanism (33) includes a first sleeve (331) arranged on the first connecting plate (31), a second sleeve (332) arranged on the second connecting plate (32), a sliding rod (333) slidably connected to the first sleeve (331) and the second sleeve (332), and a buffer (334) sleeved on the sliding rod (333), and limit blocks (335) are arranged at both ends of the sliding rod (333) for preventing the sliding rod (333) from slipping. The inner diameters of the first sleeve (331) and the second sleeve (332) are larger than the outer diameter of the sliding rod (333) to form an offset gap.

3. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 1 or 2, characterized in that: The walking mechanism (4) comprises a driving wheel (41) arranged on the equipment main body (1), a telescopic wheel group (42) arranged on the equipment main body (1) and capable of being telescopic in a horizontal direction, a first guide wheel group (43) arranged on the equipment main body (1), a second guide wheel group (44) arranged on the welding working device (2), and a lifting mechanism for driving the telescopic wheel group (42) to move in a vertical direction.

4. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 3 is characterized in that: The first guide wheel set (43) and the second guide wheel set (44) are both distributed in an eight-shaped shape.

5. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 3 is characterized in that: The first positioning mechanism (5) comprises a side main support mechanism (51) arranged on the main body (1) of the equipment and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe, and a side auxiliary support mechanism (52) arranged on the main body (1) of the equipment and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe. The side main support mechanism (51) comprises a first support cylinder (511) capable of being extended and retracted in the horizontal direction and an arc-shaped support block (512) arranged on the free end of the first support cylinder (511) and adapted to the inner wall of the steel pipe. The side auxiliary support mechanism (52) has the same structure as the side main support mechanism (51).

6. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 5, characterized in that: The side main support mechanism (51) is arranged on an end of the device main body (1) away from the telescopic wheel group (42), and the side auxiliary support mechanism (52) is arranged on an end of the device main body (1) close to the telescopic wheel group (42), and the support area of ​​the arc-shaped support block (512) on the side main support mechanism (51) is larger than the support area of ​​the arc-shaped support block (512) on the side auxiliary support mechanism (52).

7. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 5, characterized in that: The second positioning mechanism (6) comprises an annular positioning frame (61) arranged on the welding working device (2), a second supporting oil cylinder (62) evenly arranged along the circumference of the annular positioning frame (61), a balancing frame (63) arranged on the free end of the second supporting oil cylinder (62), a ball (64) arranged on the balancing frame (63), and a pressure sensor for monitoring the oil pressure of the second supporting oil cylinder (62); the free end of the second supporting oil cylinder (62) is connected to the balancing frame (63) via a universal joint (65), and the second supporting oil cylinder (62) and the pressure sensor are arranged in a one-to-one correspondence.

8. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 7, characterized in that: The welding working device (2) comprises a track mechanism (22), a welding mechanical arm (21), a connecting sleeve (23) and a welding wire feeding mechanism (24); the track mechanism (22) comprises an annular track (221) arranged on the connecting sleeve (23), a driving rack (222) arranged on the annular track (221) and a moving carriage (223) arranged on the driving rack (222); the welding mechanical arm (21) comprises a connecting sleeve (23) and a connecting sleeve (23); and the connecting sleeve (23) comprises a connecting sleeve (23) and a connecting sleeve (24). A mechanical arm (211) on a trolley (223), a welding gun (212) arranged on the mechanical arm (211) and a visual system, the welding wire feeding mechanism (24) comprises a side frame (241) connected to the connecting device (3), a wire feeder (242), a welding wire reel (243) and a gun cleaner are arranged on the side frame (241), one end of the connecting sleeve (23) is connected to the side frame (241), and the other end is connected to the annular positioning frame (61).

9. The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 1, characterized in that: The equipment host (1) comprises a host body (11), on which a power supply (12), an electric control box (13), a pump station (14) and a mounting plate (15) for connecting the connecting device (3) are arranged.

10. An automatic welding method for inner annular seam of large diameter steel pipe, characterized in that: The automatic welding equipment for inner annular seam of large diameter steel pipe according to claim 8 comprises the following steps: S1. According to the diameter of the steel pipe to be welded, the installation positions of the connecting device (3) and the side frame (241) and the extension length of the second positioning mechanism (6) are adjusted, and the lifting mechanism is adjusted so that the horizontal extension direction of the telescopic wheel group (42) coincides with the horizontal radial direction of the steel pipe to be welded; S2, retracting the first supporting oil cylinder (511), the telescopic wheel group (42) and the second supporting oil cylinder (62), hoisting the inner annular seam automatic welding equipment of the large-diameter steel pipe into the assembled steel pipe to be welded; S3, extending the telescopic wheel group (42) so that the telescopic wheel group (42) is rollingly connected to the inner wall of the steel pipe to be welded, extending the second supporting oil cylinder (62) so that the ball (64) of the balance frame (63) at the bottom end of the annular positioning frame (61) is rollingly connected to the inner wall of the steel pipe to be welded, starting the walking mechanism (4) to drive the automatic welding equipment for the inner annular seam of the mobile large-diameter steel pipe to move to the working place, and ensuring that the distance between the welding robot arm (21) and the weld is within a preset range; S4, extending the first supporting oil cylinder (511) so that the arc-shaped supporting block (512) of the side main supporting mechanism (51) and the arc-shaped supporting block (512) of the side auxiliary supporting mechanism (52) abut against the inner wall of the steel pipe to be welded, and adjusting and fixing the relative position of the main machine (1) and the steel pipe to be welded; S5, extending the second supporting oil cylinder (62) so that the balls (64) on all the balancing frames (63) abut against the inner wall of the steel pipe to be welded, thereby positioning the relative position of the welding working device (2) and the steel pipe to be welded; S6, start the visual system to check the positioning of the track mechanism (22), the welding robot arm (21) and the equipment status of the wire feeder (242), the robot arm (211) and the welding gun (212); S7. Carry out preparatory work before welding, grind and preheat the annular seam; S8, Circumferential seam automated welding and root cleaning; S9, weld post-processing, completing the welding of a circumferential seam; S10, retracting the second supporting oil cylinder (62), keeping the ball (64) of the balancing frame (63) at the bottom end of the annular positioning frame (61) in rolling connection with the inner wall of the steel pipe to be welded, retracting the first supporting oil cylinder (511), so that the arc-shaped supporting block (512) of the side main supporting mechanism (51) and the arc-shaped supporting block (512) of the side auxiliary supporting mechanism (52) are out of contact with the inner wall of the steel pipe to be welded; S11. Repeat steps S3 to S10 to weld the next annular seam.

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